Ford vs Chevy Build-up

[fordteacherguy]

Rich,
These older Ford EFI systems didn't give live data so as Ford Tech we installed a "break out box) interface between the EEC processor and harness that had exposed pins where we could measure the pin voltages with a digital volt meter. You can do similar sensor checks with a thin paperclip and your voltmeter by slipping the clip along side the sensor wire in the sensors backshell until it hits the connector (back probing) and directly measure voltage coming from the sensor wire to ground and comparing to spec. Most 3 wire sensors have a wire that is 5V reference (orange) Sensor Ground (Black) and sensor output (green or some other color). I just probe and can identify signal wire (usually the one in the middle) that has the voltage between o and 5. Two wire sensors (IAT and ECT) jut tap into either ide and read voltage. Take readings with sensors hooked up.

Typical Values at idle and warm

TP around 1 volt
Baro 159 HZ +/-6 (Frequency, set meter on HZ)
ECT 1,3-..6 Warm
IAT 1.3 -.6 Warm
MAF 1V-? More with more air going through.

Make sure MAF wire is clean and doesn't have contaminants on it...maf is a major player with A/F.

Good luck!